There is disclosed in U.S. Pat. No. 5,158,481, a shielded electrical connector comprising; a terminal support block encircled by a housing with a mating end, contact terminals supported on the block for connection to conductors, and shielding for the connector comprising; a front shell on the housing, a mating end on the front shell encircling the terminal support block, and conductive backshells enveloping the block.
The backshells and front shell are assembled by hooks passing through slots in the front shell. Compression beams near the hooks pressed against the front shell to establish electrical continuity between the front shell and the backshells.
The components, for example, the terminal support block and the housing and the front shell are separate components, manufactured with dimensions that vary within a permitted range of dimensional tolerances. These tolerances allow the components to interfit when combined together in a connector. These tolerances accumulate when the components are combined, and allow the components to shift their positions relative to one another in an assembled connector. Shifting of the components is especially detrimental when the connector undergoes mating connection with another, mating electrical connector. Such shifting, which occurs during mating connection, tends to move the terminal support block rearwardly with respect to the mating ends of both the housing and the front shell. The contact terminals supported on the block move rearwardly with the block during mating connection. Rearward movement of the contact terminals is not desired during mating connection, since rearward movement of the contact terminals tends to disconnect the connector from another, mating electrical connector. Furthermore, during mating connection, the contact terminals undergo desired contact wiping to dislodge nonconductive oxides and other contaminants that would contribute to an undesired voltage drop across the surfaces of the contact terminals. The contact wiping occurs when the contacts of the connector stroke against mating contacts of another, mating electrical connector, as the connectors undergo mating connection. The stroke is reduced when the contact terminals move rearwardly. Consequently, the contact wiping is reduced when the terminals move rearwardly due to shifting of the components.